[111.02] Continued Investigations of the Galactic Microquasars with RXTE

The 1996-1997 outburst in GRO J1655-40 has ended,
and we may now assess the spectral evolution of this
episode. There are 4 distinct branches of QPO activity,
and 3 of these are clearly related to the strength of the
power-law (Compton) component of the X-ray spectrum.
When this component is brightest, the source begins to
resemble the stable, bright states seen in GRS1915+105.
Meanwhile, GRS1915+105 continues to cycle between its four
emission states. The 67 Hz oscillation has been detected
on many occasions. We summarize the observational
constraints on the origin of the Compton component and
qhe associated QPOs.